An automatic mesh division method for watershed simulation of ship roll damping viscous flow

Abstract

The invention belongs to the field of ship roll damping virtual test automation, in particular to an automatic grid division method for a ship roll damping viscous flow simulation watershed. Including determining various parameters of a given ship type; determining the computational domain, determining the size of the box and the number of encryptions according to the box-like encryption criterion; formulating the surface refinement level; determining the thickness of the first layer of the boundary layer mesh; formulating the mesh based on the minimum mesh size Quality standards; determine the standards for mesh refinement, fit and boundary layer addition, and formulate a hull mesh division plan; complete the preset parameters, and the hull mesh is automatically divided; grid. The invention adopts the three-dimensional meshing tool snappyHexMesh that comes with OpenFOAM, and proposes a general automatic meshing method and a configuration criterion for dictionary file parameters, so as to control the number and size of the meshes, and ensure the addition rate of the boundary layer. The automatic division of the ship roll damping test grid is realized, and the application prospect is broad.

Description

technical field [0001] The invention belongs to the field of ship roll damping virtual test automation, in particular to an automatic grid division method for a ship roll damping viscous flow simulation watershed. Background technique [0002] As a key part of the automation process of the ship roll damping virtual test, the automatic division of the grid determines the automation degree of the roll damping numerical simulation. The meshing tool snappyHexMesh is a method of meshing with preset parameters, which can automatically generate hexahedral and polyhedral meshes from STL and OBJ geometric model files. Iteratively refines an initial mesh, removing more than 50% of the volume inside the geometry, and deforming the refined mesh to adhere to the surface. After this process there is an option to insert a mesh boundary layer or not. Mesh fitting, the process of adding boundary layers is controlled by a pre-defined mesh quality standard, which is very flexible, and the su...

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Problems solved by technology

Mesh refinement will also result in smaller mesh sizes, smaller calculation time steps, and longer numerical simulation cycles.

At present, snappyHexMesh is used to carry out ship roll damping grid division, but there is still a lack of efficient and accurate automatic grid division process and method, which is not convenient for the industrial promotion and application of ship roll damping virtual test

[0004] At present, most of the numerical simulation of ship rolling still relies on other meshing software to generate grids and then import them into CFD software for calculation. However, using commercial software to divide meshes requires a certain operating foundation, and importing them into some CFD software such as OpenFOAM is still difficult. It is necessary to modify the composition and format of the grid file before it can be used for calculation. This method has a high threshold, complicated process and time-consuming

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